Registration Dossier

Administrative data

Description of key information

In vitro skin irritation and corrosion assessment in a reconstructed human epidermis model (EpiSkin) (OECD439).
In vivo skin irritation/corrosion test in the rabbit (OECD404).
In vitro eye irritation/corrosion test (BCOP) (OECD437).
In vivo eye irritation test in the rabbit (OECD405).

Key value for chemical safety assessment

Skin irritation / corrosion

Endpoint conclusion
Endpoint conclusion:
adverse effect observed (irritating)

Eye irritation

Endpoint conclusion
Endpoint conclusion:
adverse effect observed (irritating)

Respiratory irritation

Endpoint conclusion
Endpoint conclusion:
no study available

Additional information

The skin irritation potential of potassium dicyanoaurate was tested in vivo on rabbit skin. A solution of 0.5 g potassium dicyanoaurate in water was applied occlusively to three rabbits for four hours, followed by a 14-day observation period, according to OECD guideline 404 and EU method B.4 (Berthold 1992). Severe reactions were observed in all animals. Potassium dicyanoaurate was determined to be highly irritating. Skin irritation and corrosion were also tested with the EPISKIN reconstructed human epidermis model. Triplicate tissue samples were exposed to approximately 10 mg potassium dicyanoaurate applied topically for 15 minutes followed by a 42-hour post-exposure incubation period, according to OECD guideline 439 and EU method B.46 (Warren 2014a). Potassium dicyanoaurate is considered to be irritating based on EU criteria. In the skin corrosion test, duplicate tissue samples were exposed for 3, 60 and 240 minutes to approximately 20 mg potassium dicyanoaurate applied topically followed by a 3-hour post-exposure incubation period, according to OECD guideline 431 and EU method B.40 (Warren 2014b). Potassium dicyanoaurate is considered to be non-corrosive based on EU criteria.

Eye irritation was tested in vitro and in vivo. In the in vivo test performed according to OECD guideline 405 and EU method B.5, one rabbit was treated with a single application of 0.101 g potassium dicyanoaurate in one eye. All DRAIZE scores were at the maximum 1 hour after treatment and mortality occurred 7 hours after treatment. Severe hypokinesia and lacrimation at the non-treated eye were observed 5 hours after treatment. Potassium dicyanoaurate is considered to be corrosive to the rabbit eye (Berthold 1992). In the Bovine Corneal Opacity and Permeability (BCOP) assay following OECD guideline 437, eyes from adult cattle were treated with approximately 0.873 g of potassium dicyanoaurate for 240 minutes (Warren 2014c). Results of the opacity and permeability endpoints were combined to give an In Vitro Irritancy Score of 171.5. Potassium dicyanoaurate is considered to be an ocular corrosive or severe irritant based on EU criteria.

Overall, potassium dicyanoaurate is a skin irritant, an ocular corrosive and a severe eye irritant, but is not skin corrosive.


Justification for selection of skin irritation / corrosion endpoint:
Potassium dicyanoaurate was determined to be a highly irritating but non-corrosive to the skin in skin irritation and corrosion studies on rabbit skin and a human epidermis model. The in vivo rabbit study is considered to represent the most severe response.

Justification for selection of eye irritation endpoint:
Potassium dicyanoaurate was determined to be a severe eye irritant in the in vitro eye test and corrosive to the eye in the in vivo test. The in vivo rabbit study is considered to represent the most severe response.

Effects on skin irritation/corrosion: highly irritating

Effects on eye irritation: corrosive

Justification for classification or non-classification

According to GHS and EU CLP 1272/2008, potassium dicyanoaurate is classified as Category 2 for skin irritation, based on the results of in vivo rabbit and in vitro human epidermis model studies, and Category 1 (serious eye damage/irreversible effects on the eye) for effects on the eye, as serious eye damage was observed the in vivo eye irritation and BCOP studies.